What do you average for 60' time now?
The front end is important too. Do you have the travel to take advantage of cal-tracs? What are you using for shocks in the front?
My car runs very consistent low 7.50s, and 60' averages 1.54 with the cal-tracs, springs, and their shocks. I have tweaked on it a fair bit, but I am sure there is more in it. Kind of lost incentive to find it since I run 12.00 and 7.50 index and the car seems to run that all the time.